ACANTHOCLADIIDAE Ulrich, 1890

Ernst, Andrej, Wyse Jackson, Patrick N. & Aretz, Markus, 2015, Bryozoan fauna from the Mississippian (Visean) of Roque Redonde (Montagne Noire, southern France), Geodiversitas 37 (2), pp. 151-213 : 192

Family ACANTHOCLADIIDAE Ulrich, 1890

Genus Diploporaria Nickles & Bassler, 1900

TYPE SPECIES. — Glauconome (Diplopora) marginalis Young & Young, 1875 by original designation. Lower Carboniferous (Visean) ; British Isles.

DIAGNOSIS. — Colony consisting of thin main branches and rare lateral branches of identical morphology. Both main and lateral branches bearing two rows of autozooecia.

OCCURRENCE. — Lower Carboniferous – Lower Permian; Europe, USA, Asia.

COMPARISON

Diploporaria Nickles & Bassler, 1900 differs from Penniretepora d’Orbigny, 1849 in rare lateral branches, whereas Penniretepora possesses a pinnate colony with regularly arranged lateral branches either side of the main branch.

Diploporaria tenella Wyse Jackson, 1988 ( Figs 26 F-H, 27A; Appendix)

Diploporaria tenella Wyse Jackson, 1988: 201 , fig. 1b, 2b, 4d-f, 7a, b; 1996: 141, 142, fig. 42a, 45. — Wyse Jackson & Weber 2005: 377, fig. 1a.

MATERIAL. — SMF 21.923- SMF 21.925, TCD.60336, 60337, 60340, 60342.

OCCURRENCE. — Carboniferous, Mississippian (Visean); Ireland, Germany (Velbert Anticline, Rhenish Massif), Roque Redonde (Montagne Noire, southern France).

DESCRIPTION

Colony consisting of straight branches bifurcating nearly at right angle.Branches 0.29-0.32 mm wide. Autozooecia arranged in 2 alternating rows on branches. Autozooecial apertures rounded to oval, with smooth peristome, 0.085 -0.095 mm in diameter, spaced 0.32-0.43 mm (0.38 mm at average) from centre to centre.Single sharp node on the peristome, directed proximally. Autozooecial chambers long, subrectangular in the mid tangential section. Superior hemisepta long, curved distally; inferior hemisepta absent. External laminated skeleton thin. Branch reverse side smooth. Heterozooecia not observed.

COMPARISON

Diploporaria tenella Wyse Jackson, 1988 possesses distinctive elongate quadrate-shaped autozooecial chambers in midtangential section which separates it from other Diploporaria species. Externally D. tenella resembles D. bifurcata ( Ulrich, 1890) with a sinuous branch margin, although apertures are more widely spaced in the latter. D. tenella differs from the type species D. marginalis which has trapezoidal-shaped chambers, and a well-developed peristome that projects beyond branch margins producing a strongly serrated outline.

Figures

FIG. 26. — A, Polypora dendroides M’Coy, 1844, longitudinal section, SMF 21.919. B-E, Polypora marginata M’Coy, 1844, SMF 21.921; B-D, mid-tangential section showing autozooecial chambers and apertures; E, tangential section showing autozooecial apertures, undulatory striations and branch surface; F-H, Diploporaria tenella Wyse Jackson, 1988, mid-tangential section showing autozooecial chambers with hemisepta (arrow) and apertures, SMF 21.923. Scale bars: A, G, 0.5 mm; B, C, F, 2 mm; D, E, 1 mm; H, 0.2 mm.